Those shapes are not very hard to make…
just make the plug like you Want it Make it nice and smooth, Get some plexiglass or Lexan (I like it better to work with) clamp the sheet into a frame…
build a table with a hole in the middle to hook up the hose of your shop vac…set the plug with little spacers on the table over the hole..
Hold the frame with the Lexan horizontally and heat it with a heatgun gently up until the sheet starts bowing evenly down..
now take the whole frame and gently put it over the plug.. Frame touching the table all the way around evenly and turn on the vacuum cleaner… puff - done..✅
just trim..